Design of quasi-grain-boundary-free (QGBF) polycrystalline solar cells

A new solar cell structure is proposed which will increase the efficiency of polycrystalline solar cells by suppressing or completely eliminating the recombination losses due to the presence of grain boundaries. This is achieved by avoiding the formation of the p-n junction (or other types of junctions) in the grain boundaries and by eliminating the grain boundaries from the active area of the cell. This basic concept can be applied to any polycrystalline material; however, it will be most beneficial for cost-effective materials of the future, i.e., materials having small grains, including thin film materials. The concept is demonstrated to be technologically achievable.